1. Field of the Invention
The present invention deals with a heat sink for cooling an electron device or electronic device such as an IC (i.e., Integrated Circuit) or an IC chipset by radiating heat thereof into the air.
2. Discussion of the Related Art
U.S. Pat. Nos. 6,102,110 and 7,143,819 disclose devices for cooling an electron device by transporting heat generated by the electron device to a portion away from a contact portion of the electron device to radiate the heat therefrom. According to the structure taught by U.S. Pat. No. 6,102,110, one of the end portion of a plurality of heat exchange tubes are secured in a rigid plate, and the other end portion of the heat exchange tubes are protruded from the rigid plate. A plurality of heat radiation fins are mounted on the protruded portion of the heat exchange tubes and electronic power components are attached to the rigid plate. Therefore, heat of the electronic power components are transported to the fins through the heat exchange tubes, and radiated from the fins into the air.
Meanwhile, U.S. Pat. No. 7,143,819 discloses a heat sink, in which an L-shaped or a U-shaped heat pipe provided with heat radiation fins is directly contacted with an electronic component. According to the heat sink suggested by U.S. Pat. No. 7,143,819, heat of the electronic component is transported to the fins through the heat pipe, and radiated from the fins into the air.
Additionally, in the prior art, there is known a heat sink, in which a plurality of heat radiation fins are provided on a top face of a base plate, and a heat receiving portion to be contacted with an electronic component is formed on a bottom face of the base plate.
However, the heat sink or the radiation device suggested by U.S. Pat. Nos. 6,102,110 and 7,143,819 transports the heat of the electron device to the fins by the heat pipe. This means that a large quantity of heat pipes are necessary for those prior art devices. For this reason, such prior art devices have to be dimensionally enlarged and a manufacturing cost thereof also be increased.
As to the aforementioned heat sink of the prior art, in which a plurality of heat radiation fins are provided on a top face of a base plate, the base plate is made of a metal sheet so that the heat capacity thereof is large. This means that thermal resistance between the electron device and the heat radiation fins is large, and this degrades the cooling performance to cool the electron device. Additionally, the heat radiation from the fins is promoted by the air flowing around the fins; however, the direction of the airflow is restricted to the direction in parallel with the top face of the base plate. For this reason, heat radiating efficiency of the heat sink of this kind is not sufficiently high enough.